The present invention relates to an indicating device for vehicles.
It is known that provide in vehicles, in particular in motor vehicles indicating devices having a so-called head-up-display device which projects an indicator supplied by an indicating device onto a projection surface in front of a driver""s seat and visually superposes a virtual image of the indicator of the outer landscape before the windshield. These indicating devices as a rule have a projector cooperating with an indicator which throws the light emitted by the indicator against the windshield. The windshield acts as a combining element and reflects the light and thereby makes ready a visible image for the driver as a virtual image before the windshield. This mirror-reflected information can be positioned at the end of the visible field of the driver at different heights. Important or hazard indicating informations can be also shown in the windshield center. Preferably with such virtual images, their visual position is in a region of several meters in front of the windshield, so that the driver for determination of these informations must neither use the glance on the windshield nor his eyes must be adjusted to a point inside the vehicle, mainly the indicator board. These accommodations of eyes are tiring and distract the attention of the driver for a certain time from road conditions.
Further indicating devices are known in the control panel of the vehicle such as speed, rotary speed and temperature indicators which operate analogously or are formed as digital indicating devices. Analog indicating devices can be actuated mechanically, for example through shafts or have a motor drive which is controlled by electrical sensor units. Digital indicating devices are normally controlled in electronic ways.
Further combinations of conventional indicating instruments in the control board and head-up-display devices are known, which are connected with one another mechanically, for example by a coupling of the motor-operated mechanical indicator with liquid crystal devices with optical projection system for the head-up-display. Also known further concepts for indication of for example speed and rotary speed in combined instrument by means of reverse projection of a laser beam onto a matt disc. Also it is known to use a laser as an image source for a head-up-display device.
The disadvantages of all these above mentioned concepts is a considerable structural expenses due to a required combination of individual independent indicating devices.
Accordingly, it is an object of present invention to provide a combined indicating device with a head-up-display and conventional combi instruments in a control panel, which has a simple construction.
In keeping with these objects and with others which will become apparent hereinafter, one feature of present invention resides, briefly stated, in an indicating device for a vehicle, in which the indicating device has a common information source which serves simultaneously with an information image forming on the instrument board in the control board and for an information forming as a virtual image on the windshield of the vehicle.
When the device is designed in accordance with the present invention, the indicating devices in the instrument board and the head-up-indicator forming in the windshield of the vehicle as a virtual image are provided in a simple and cost-favorable manner by an integrated unit with a common laser light source. The utilization of the laser light for image forming of the information which is important for the driver has the special advantage, that this light source can be superposed or modulated with all informations to be brought for indication. The laser light can be relatively easily provided both for polarization and for pulsing, and thereby for separation into several beam bundles with corresponding different indication informations.
When compared with other light sources, the laser light in addition has the advantage of very high light density, which in correspondence with a required indicating brightness can be modified or weakened relatively easy. For example, the outer light impingement on the windshield and the instrument panel can be detected by suitable sensors, and in dependence on the determined brightness values, the brightness of the laser light can be adjusted fast. In particular, during the day the very strong sun radiation can make a head-up-indicator difficult to read. This can be completely compensated by the high light densities of the laser light.
It is also advantageous that an optical deviating device is arranged after the beam bundle emitted by the laser light source and serves for a flat image forming of the indication information contained in the modulated laser light. This optical deviating device is preferably coupled so with a control unit for the laser light, so that periodically several beam bundles are formed with high frequency which are perceived by human eye of the driver as permanent indicators. This distribution of a single light source into several light bundles has the advantage that relatively easily several flat indicators can be controlled with high frequency switching-over, which due to repetition values of the human eye are perceived as constant indicators. The images of the beam bundles emitted by the optical deviating units can be projected by a suitable fixed or turnable mirror on matt discs. A first matt disc can be placed in the control board and projects the informations transmitted from the optical deviating device to the mirror onto the instrument panel. A second matt disc can be for example the windshield of the vehicle which projects a beam bundle deviated by a further mirror. The driver in this way can see virtual images which are located several meters from the windshield.
The combination of the instrument indicators and the head-up indicators with a common laser light source has the advantage that the driver can be presented with both indicators in a single outer appearance image. In particular, in this way an optimal determination between both indicator in types is possible. For example a danger hint can be provided in a combined form on both indicators. Possible are also alternating combination depending. on the operational condition of the vehicle. For example during sudden strong acceleration the indicator of the rotary speed meter can appear in the windshield as a head-up-indicator, so that during transition to constant driving condition to be released by the speed indicator. Such a programming has the advantage that the corresponding most important information is presented to the driver in the head-up-indicator on the windshield, to provide to him an optimal visibility in the traffic and to spare in particular the look at the instrument board. Here the informations with corresponding secondary dependence can be represented.
By suitable optical deviating and changing-over devices such as mirrors and prisms, in addition an optical utilization of the space available behind the control panel of the vehicle is possible. For example by suitable extension of the voluminous components in the region which is farther from the driver, a structural freedom can be provided in the vehicle for example for actuating levers or air guiding and outflow elements.
It is also recommended that the indicating devices for the outer radio or a navigation system be brought in position which is more suitable optically for the driver than in the conventional mounting locations, mainly in the central console. With the navigation aids with relatively small image screen representation, the deviation effect for the driver is very high. Such indicators can be easily integrated in an indicating device in accordance with the present invention and increase substantially the attention of the driver and thereby the driving safety.
The novel features which are considered as characteristic for the present invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.